The physiology of chilling injured longan fruit

Abstract

Abstract
It is known very well that longan fruit was easily deteriorated during storage at low
temperature. Longan pulp, translucent aril, generally contains high amount of sugars while the
longan peel, yellowish-brown pericarp, consists of high phenolic substances. In this study,
longan fruits were kept at low temperature (4ºC) to investigate the changes of pulp and peel
properties. It was found that longan peel was obviously malformation as a result of the
increasing in an electrolyte leakage value, hardness and discoloration. The dry peel then
reabsorbed water that caused swelling and disintegrating. The pulp color altered from
translucent white to light yellow since the polyphenol oxidase activity dramatically increased.
The pulp also contained more juice after longer storage. However, it is still difficult to identify
the symptoms of chilling injury on longan pulp. One possibly involved factor is the electrolyte
leakage value as it increased during storage.
Keywords: discoloration, polyphenol oxidase, electrolyte leakage, longan